Improve diagram readability

Author: wutongci

docs/.vitepress/theme/custom.css

@@ -128,3 +128,52 @@
     min-width: 520px;
   }
 }
+
+/* Diagrams are evidence, not decoration: keep them readable on desktop and scrollable on mobile. */
+.vp-doc .ac-mermaid {
+  margin: 2rem calc((min(100vw, 1280px) - 100%) / -2);
+  padding: 1.25rem;
+}
+
+.vp-doc .ac-mermaid__canvas {
+  min-width: 1180px;
+}
+
+.vp-doc .ac-mermaid__canvas svg {
+  display: block;
+  width: auto;
+  min-width: 1500px;
+  max-width: none;
+  margin: 0 auto;
+}
+
+.vp-doc img[src$="harness-engine-shift.svg"] {
+  display: block;
+  width: min(1180px, 100%);
+  max-width: 1180px;
+  margin: 1.5rem auto 2rem;
+  border: 1px solid var(--vp-c-divider);
+  border-radius: 20px;
+  background: var(--vp-c-bg-soft);
+}
+
+@media (max-width: 760px) {
+  .vp-doc .ac-mermaid {
+    margin-left: -1rem;
+    margin-right: -1rem;
+    border-radius: 0;
+  }
+
+  .vp-doc .ac-mermaid__canvas {
+    min-width: 960px;
+  }
+
+  .vp-doc .ac-mermaid__canvas svg {
+    min-width: 760px;
+    width: auto;
+  }
+}
+
+.vp-doc .ac-mermaid__canvas svg[viewBox] {
+  min-width: 1500px;
+}

docs/workflow/overview.md

@@ -4,7 +4,7 @@ AI Coding 的关键不是“让 AI 多写”，而是让每个阶段都有明确
 
 ```mermaid
 flowchart LR
-  A[PRD/Issue] --> B[任务切片]
+  A[PRD / Issue] --> B[任务切片]
   B --> C[上下文包]
   C --> D[实现 Agent]
   D --> E[自检]
@@ -15,7 +15,7 @@ flowchart LR
   H --> I
   I --> J{人类裁决}
   J -->|修复| D
-  J -->|接受| K[发布/灰度]
+  J -->|接受| K[发布 / 灰度]
   K --> L[反馈学习]
   L --> A
 ```